Method for preparing hydro/organo gelators from disaccharide sugars by biocatalysis and their use in enzyme-triggered drug delivery

ABSTRACT

A method for preparing hydro/organo gelators from disaccharide sugars by biocatalysis and their use in enzyme-triggered drug delivery. Controlled delivery of an anti-inflammatory, chemopreventive drug is achieved by an enzyme-triggered drug release mechanism via degradation of encapsulated hydrogels. The hydro- and organo-gelators are synthesized in high yields from renewable resources by using a regioselective enzyme catalysis and a known chemopreventive and anti-inflammatory drug, curcumin, is encapsulated in the gel matrix and released by enzyme triggered delivery. The release of the drug occurs at the physiological temperature and control of the drug release rate is achieved by manipulating the enzyme concentration and temperature. The by-products formed after the gel degradation clearly demonstrated the site specificity of degradation of the gelator by enzyme catalysis. The present invention has applications in developing cost effective, controlled drug delivery vehicles from renewable resources, with a potential impact on pharmaceutical research and molecular design and delivery strategies.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to hydro/organo gelators, and moreparticularly, the present invention relates to a method for preparinghydro/organo gelators from disaccharide sugars by biocatalysis and theiruse in enzyme-triggered drug delivery, cosmetic components delivery, andmaking of templated materials to generate inorganic and softnanomaterials.

2. Description of the Prior Art

Use of renewable resources for production of valuable chemicalcommodities is becoming a topic of great interest and an objective ofpromoting the industrial bio-refinery concept in which a wide array ofvaluable chemicals, fuel, food, nutraceuticals, and animal feed productsall result from the integrated processing of grains, oil seeds, andother biomass materials.¹ ¹Lorenz, P. & Zinke, H. White biotechnology:differences in US approaches? Trends Biotechnol. 23, 570-574 (2005);Business and regulatory news. OECD says industrial biotech not realizingpotential. Nat. Biotechnol. 19, 493-494 (2001).

An article by Stephan Harrera² illustrates that industrial or ‘white’biotechnology³ is making an increasingly important contribution to thedevelopment of a sustainable, biobased economy by an environmentalbenign approach.⁴ It uses enzymes and micro-organisms to make productsin sectors, such as chemistry, food and feed, paper, textile, andmedicine. As opposed to chemical synthesis, enzyme catalysis is highlyselective and has been used to generate various specialty chemicals,⁵including sugar-based esters.⁶ ²Herrera, S. Industrial biotechnology-achance at redemption. Nat Biotechnol. 22, 671-675 (2004).³Industrialbiotechnology and sustainable chemistry. Royal Belgian Academy ofApplied Sciences, Brussels (January 2004).⁴Eissen, M., Metzger, J. 0.,Schmidt, E. & Schneidewind, U. 10 Years after rio-concepts on thecontribution of chemistry to a sustainable development. Angew. Chem.Int. Ed 41, 414-436 (2002); Biermann, U. et al. New synthesis with oilsand fats as renewable raw materials for the chemical industry. Angew.Chem. Int. Ed. 39, 2206-2224 (2000); Gibson, J. M. et al. Benzene-freesynthesis of phenol. Angew. Chem. Int. Ed. 40, 1945-1948(2001).⁵Wandrey, C., Liese, A. & Kihumbu, D. Industrial biocatalysis:past, present and future. Org. Process Res. Dev. 4, 286-290 (2000).⁶Yan,Y., Bornschener, U. T. & Schmid, R. D. Lipase-catalyzed synthesis ofvitamin C esters. Biotechnol. Lett. 21, 1051-1054 (1999).

Thus, there exists a need for developing building blocks from renewableresources to generate soft nanomaterials, such as new surfactants,liquid crystals, organic gelling materials, and hydrogels.⁷ ⁷John, G.,Masuda, M. & Shimizu, T. Nanotube formation from renewable resources viacoiled nanofibers. Adv. Mater. 13, 715-718 (2001); John, G., Masuda, M.,Jung, J. H., Yoshida, K. & Shimizu, T. Unsaturation influenced gelationof aryl glycolipids. Langmuir 20, 2060-2065 (2004); John, G., Mason, M.,Ajayan, P. M. & Dordick, J. S. Lipid-based nanotubes as functionalarchitectures with embedded fluorescence and recognition capabilities.J. Am. Chem. Soc. 126, 15012-15013 (2004).

Hydrogels have a range of biomedical applications in areas such astissue engineering,⁸ controlled released drug delivery systems,⁹ andmedical implants.¹⁰ Design and synthesis of low-molecular-weighthydrogelators has received considerable attention in soft materialsresearch in terms of its potential applications in cosmetics,toiletries, and pharmaceutical formulations. Literature study revealsthat there are only limited reports on easily achievable and efficientlow-molecular-weight gelators that are able to gel water or even watermixtures with other solvents,¹¹ and which are often achieved bymulti-step chemical synthesis. Surprisingly, to the best of applicants'knowledge, to date there are no examples in the literature wherelow-molecular-weight hydrogelators were synthesized from renewableresources by using regioselective enzyme catalysis. ⁸Lee, K. Y. &Mooney, D. J. Hydrogels for tissue engineering. Chem. Rev. 101,1869-1879 (2001).⁹Friggeri, A., Feringa, B. L. & van Esch, J. Entrapmentand release of quinoline derivatives using a hydrogel of low molecularweight gelator. J. Controlled Release 97, 241-248 (2004); Yang, Z.,Liang, G., Wang, L. & Xu, B. Using a kinase/phosphatase switch toregulate a supramolecular hydrogel and forming the supramolecularhydrogel in vivo. J. Am. Chem. Soc. DOI:10.1021/j057412y (2006); vanBommel, K. J. C., Stuart, M. C. A., Feringa, B. L. & van Esch, J.Two-stage enzyme mediated drug release from LMWG hydrogels. Org. Biomol.Chem. 3, 2917-2920 (2005).¹⁰Lee, K. Y. & Mooney, D. J. Hydrogels fortissue engineering. Chem. Rev. 101, 1869-1879 (2001); Miyata, T.,Uragami, T. & Nakamae, K. Biomolecule-sensitive hydrogel. Adv. DrugDelivery Rev. 54, 79-98 (2002).¹¹Menger, F. M. & Caran, K. L. Anatomy ofa gel. Amino acid derivatives that rigidify water at submillimolarconcentrations. J. Am. Chem. Soc. 122, 11679-11691 (2000); Jokic, M.,Makarevic, J., Zinic, M. & Makarevic, J. A novel type of small organicgelators: bis(amido acid) oxalyl amides. J. Chem. Soc., Chem. Commun.1723-1724 (1995); Makarevie, J. et al. Bis(amino acid) oxalyl amides asambidextrous gelators of water and organic solvents: supramolecular gelswith temperature dependent assembly/dissolution equilibrium. Chem. Eur.J. 7, 3328-3341 (2001); Oda, R., Huc, I. & Candau, S. J. Geminisurfactants as new, low molecular weight gelators of organic solventsand water. Angew. Chem. Int. Ed. 37, 2689-2691 (1998); Estroff, L. A. &Hamilton, A. D. Effective gelation of water using a series of bis-ureadicarboxylic acids. Angew. Chem. Int. Ed. 39, 3447-3450 (2000);Kobayashi, H. et al. Molecular design of “super” hydrogelators:understanding the gelation process of azobenzene-based sugar derivativesin water. Org. Lett. 4, 1423-1426 (2002); Luboradzki, R., Gronwald, O.,Ikeda, M., Shinkai, S. & Reinhoudt, D. N. An attempt to predict thegelation ability of hydrogen-bond-based gelators utilizing a glycosidelibrary. Tetrahedron 56, 9595-9599 (2000); Gronwald, 0. & Shinkai, S.Sugar-integrated gelators of organic solvents. Chem. Eur. J. 7,4328-4334 (2001); Jung, J. H. et al. Self-assembly of a sugar-basedgelator in water: Its remarkable diversity in gelation ability andaggregate structures. Langmuir 17, 7229-7232 (2001); Wang, G. &Hamilton, A. D. Low molecular weight organogelators for water. Chem.Commun. 310-311 (2003).

Thus, there exists a need to use biocatalysis as a tool to make gelatorsfrom biomass and their assembly to form hierarchical superstructures inwater, i.e., formation of hydrogel and soft nanomaterials, encapsulationof hydrophobic drug or hydrophobic cosmetic components, as well asenzyme mediated hydrogel degradation, which will give new insights intolow-molecular-weight hydrogelators-based drug delivery.

Controlled delivery of drugs or cosmetic material occurs when a polymer,whether natural or synthetic, is judiciously combined with a drug orother active agent in such a way that the active agent is released in apre-designed manner.¹² While these advantages can be significant, thepotential disadvantages cannot be ignored, such as the possible toxicityor non-biocompatibility of the materials used, the undesirableby-products from gel degradation, and the higher cost ofcontrolled-release systems compared with traditional pharmaceuticalformulations. ¹²Dorski, C. M., Doyle, F. J. & Peppas, N. A. Preparationand characterization of glucose-sensitive P(MMA-a-EG)hydrogels. Polym.Mater. Sci. Eng. Proceed. 76, 281-282 (1997); Vert, M., Li, S. &Garreau, H. More about the degradation of LA/GA derived matrices inaqueous media. J. Controlled Release 16, 15-26 (1991).

Thus, there exists a need for sugar amphiphiles by regioselectivesynthesis of amygdalin esters as new hydrogelators, which are low cost,efficient, safe, and with high gelation efficiency.

[O-β-D-glucopyranosyl-(1-6)-β-D-glucopyranosyloxy]benzeneacetonitrileknown as D-Amygdalin is a naturally occurring glycoside found in manyfood plants, for example, the kernels of apples, almonds, peaches,cherries, and apricots.¹³ Amygdalin (a by-product of apricot, almondsand peach industry, see FIG. 1, which are pictures of: (a) an apricotpit that is a source of amygdalin; (b) Curcuma longa; and, (c) powderedcurcumin¹⁴ that is commonly known as turmeric and used in traditionalIndian culinary and medicine—has been used as a main ingredient incommercial preparations of laetrile, a purported therapeutic agent.¹⁵¹³Jones, D. A. Why are so many food plants are cyanogenic?Phytochemistry 47, 155-162 (1998).¹⁴Curcumin is just one example as adrug model.¹⁵Turczan, J. W. & Medwick, T. Qualitative and quantitativeanalysis of amygdalin using NMR spectroscopy. Anal. Lett. 10, 581-590(1977); Syrigos, K. N., Rowlinson-Busza, G. & Epenetos, A. A. In vitrocytotoxicity following specific activation of amygdalin by β-glucosidaseconjugated to a bladder cancer-associated monoclonal antibody. Int. J.Cancer 78, 712-719 (1998).

Thus, there exists a need to synthesize amygdalin derivatives that canform nanoaggregates through self-assembly and encapsulation of ahydrophobic drug followed by release of the encapsulated drug uponenzyme mediated degradation, i.e., enzyme-triggered drug-delivery.

In amygdalin-fatty acid conjugates, sugar moiety can facilitate thestacking of molecules through hydrogen bonding, phenyl ring canfacilitate intermolecular interactions through π-π stacking, andhydrophobic hydrocarbon chain not only decreases the solubility inwater, it also helps the molecular association through the van der Waalsinteractions.

In general, multi-step synthesis, arduous separation procedures, andlower yields often keep low-molecular-weight gelators away fromcommercial use due to high production cost. Strikingly, thehydrogelators of the present invention were synthesized from renewableresources in a single-step process in high yields (>90%), and unpurifiedcrude products showed unprecedented gelation abilities like theircounter pure products, allowing the development of versatile gelatorswhich can be made from low cost starting materials and withoutpurification.

Thus, there exists a need for gelator molecules with various chainlengths. See FIG. 2, which is a synthetic scheme of amygdalin-basedamphiphiles.

SUMMARY OF THE INVENTION

Thus, an object of the present invention is to provide a method forpreparing hydro/organo gelators from disaccharide sugars by biocatalysisand their use in enzyme-triggered drug delivery, which avoids thedisadvantages of the prior art.

Briefly stated, another object of the present invention is to provide amethod for preparing hydro/organo gelators from disaccharide sugars bybiocatalysis and their use in enzyme-triggered drug delivery. Controlleddelivery of an anti-inflammatory, chemopreventive drug is achieved by anenzyme-triggered drug release mechanism via degradation of encapsulatedhydrogels. The hydro- and organo-gelators are synthesized in high yieldsfrom renewable resources by using a regioselective enzyme catalysis anda known chemopreventive and anti-inflammatory drug, curcumin, isencapsulated in the gel matrix and released by enzyme triggereddelivery. The release of the drug occurs at the physiologicaltemperature, and control of the drug release rate is achieved bymanipulating the enzyme concentration and temperature. The by-productsformed after the gel degradation clearly demonstrate the sitespecificity of degradation of the gelator by enzyme catalysis. Thepresent invention has applications in developing cost effective,controlled drug delivery vehicles from renewable resources, with apotential impact on pharmaceutical research and molecular design anddelivery strategies.

The novel features considered characteristic of the present inventionare set forth in the appended claims. The invention itself, however,both as to its construction and its method of operation together withadditional objects and advantages thereof will be best understood fromthe following description of the specific embodiments when read andunderstood in connection with the accompanying drawing.

Another object of the present invention is to provide a method forpreparing hydro/organo gelators from disaccharide sugars by biocatalysisand their use in enzyme-triggered or thermo-triggered cosmetic delivery.Controlled delivery of components of cosmetic formula is achieved by anenzyme-triggered release mechanism via degradation of encapsulatedhydrogels. The hydro- and organo-gelators are synthesized in high yieldsfrom renewable resources by using a regioselective enzyme catalysis. Therelease of the cosmetic components occurs at the physiologicaltemperature and control of their release rate is achieved bymanipulating the enzyme concentration and temperature. The presentinvention has applications in developing cost effective, controlledcosmetic delivery vehicles from renewable resources.

Another object of the present invention is to provide a method forpreparing hydro/organo gelators from disaccharide sugars by biocatalysisand their use in making templated materials to develop inorganicnanomaterials.

BRIEF DESCRIPTION OF THE DRAWING

The figures of the drawing are briefly described as follows:

FIG. 1 are pictures of: (a) an apricot pit that is a source ofamygdalin; (b) Curcuma longa; and, (c) powdered curcumin that iscommonly known as turmeric and used in traditional Indian culinary andmedicine. It is also a known chemopreventive and anti-inflammatory drug;

FIG. 2 is a synthetic scheme of amygdalin-based amphiphiles;

FIG. 3 is a table of gelation ability of amygdalin derivatives 1-3 invarious solvents;

FIG. 4 are SEM micrographs, wherein scale bar is equivalent to 1 μM, of:(a) the organogel of derivative 1 prepared from acetonitrile; (b) theaqueous gel from derivative 2; (c) the aqueous gel from derivative 3;and, (d) a higher magnification of hydrogel derivative 2;

FIG. 5 are scanning electron micrographs of curcumin-embedded hydrogelsof derivative 3;

FIG. 6 are: (a) the crystal structure analysis of derivative 1 in water;and, (b) a top view showing the π-π stacking of phenyl rings andhydrogen boding between two amygdalin molecules, wherein hydrogenbonding acts as a bridge between the stacked amygdalin molecules alongthe b-axis shown as blue arrows and between these two stacks along thea-axis shown as black arrows, and wherein: oxygen is shown as red;nitrogen is shown as blue; carbon is shown as white circles; and,hydrogen-bonding is shown as black dashed lines;

FIG. 7 are schematic representations of possible molecular packingmodels for the: (a) hydrogels; and, (b) organogels of derivative 2;

FIG. 8 are: (a) a schematic representation of drug encapsulation in asupramolecular hydrogel and subsequent release of the drug by enzymemediated degradation of hydrogel at physiological temperature; and, (b)real images of the hydrogels of derivative 3 with (i-iv) and without(v-vi) curcumin, wherein after complete gel degradation, the remainedwhite fluffy powder that settled at the bottom was characterized as awater insoluble fatty acid that formed after gel degradation by theenzyme;

FIG. 9 are UV absorption spectra of curcumin in various types ofsolution mixtures, including: (a) an curcumin-entrapped hydrogel in thepresence of an enzyme; (b) an enzyme added to the hydrogel that does notcontain curcumin; (c) an curcumin-entrapped hydrogel in the absence ofan enzyme; and, (d) a methanolic solution of curcumin;

FIG. 10 is a table of the effect of enzyme concentration and temperatureon drug release time;

FIG. 11 are a comparison of curcumin-drug-release time at differentconcentrations and different temperatures from hydrogels of amygdalinderivatives by enzyme degradation, wherein: (a) is the time required for5% release; and, (b) is the time required for 100%;

FIG. 12 is a comparison of the ¹H-NMR spectra of commercially availablestearic acid and the white fluffy solid obtained after gel degradation,which was filtered, freeze-dried, and NMR recorded in Chloroform; and

FIG. 13 is a table of the crystallographic parameters of derivative 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Synthesis ofHydrogelators by Enzyme Catalysis

By taking advantage of the supreme control on regioselectivity of enzymecatalysis, a series of amygdalin derivatives were made where selectivelyintroduced acyl moiety on primary hydroxyl group gave excellent yields.

Amygdalin is a disaccharide containing one primary hydroxyl group thatforms ester bonds with fatty acids. Vinyl esters were used as acyldonors. The detailed synthesis procedures are shown in the METHODSsection below and the synthetic route to the amphiphilic amygdalinderivatives is shown FIG. 2.

In general, multi-step synthesis, arduous separation procedures, andlower yields often keep low-molecular-weight gelators away fromcommercial use due to high production cost.¹⁶ Strikingly, thehydrogelators of the present invention were synthesized from renewableresources in a single-step process in high yields (>90%), and unpurifiedcrude products showed unprecedented gelation abilities like theircounter pure products, allowing the development of versatile gelatorswhich can be made from low cost starting materials and withoutpurification. In particular, this property gives the opportunity todevelop these gelators in industrial scales for various applications incosmetics, toiletries, drug deliveries, nanomaterials, andpharmaceutical formulations.¹⁷ ¹⁶Zhang, S. Hydrogels: Wet or let die.Nat. Mater. 3, 7-8 (2004).¹⁷Id.

Gelation Abilities of Derivatives 1-3

Amygdalin derivatives 1-3 encompass all required functional groups, suchas hydrogen bond forming ‘sugar’ headgroup, phenyl ring for π-πstacking, and hydrocarbon chain for van der Waals interactions. Thesegroups together can synergistically act to form strong intermolecularinteractions leading to the gelation. The gelation abilities of thederivatives 1-3 in water and in organic—polar and nonpolar—solvents arecompared in FIG. 3, which is a table of gelation ability of amygdalinderivatives 1-3 in various solvents.

Typically, a gelator (0.01-2 mg) in a required solvent (0.1-1 mL) washeated until the solid was completely dissolved. The resulting solutionwas slowly allowed to cool to room temperature and gelation was visuallyobserved. The gel sample obtained exhibited no gravitational flow in aninverted tube. All gels obtained were thermally reversible. Above theirgelation temperature, the gels dissolved in water but could be returnedto their original gel state upon cooling.

The amygdalin amphiphiles derivatives 1-3 showed unprecedented gelationabilities in a broad range of solvents at extremely low concentrations[0.05-0.2 wt % (MGC)], while displaying excellent thermal and temporalstabilities.

Scanning Electron Microscopic Studies

Molecular self-aggregation features can be observed on an electronmicroscope, since the initial stage of physical gelation is theself-assembly of gelator monomers. FIG. 4, which are SEM micrographs,wherein scale bar is equivalent to 1 μM, of: (a) the organogel ofderivative 1 prepared from acetonitrile; (b) the aqueous gel fromderivative 2; (c) the aqueous gel from derivative 3; and, (d) a highermagnification of hydrogel derivative 2—presents the scanning electronmicroscope (SEM) images of the organogels formed by derivative 1 shownin FIG. 4( a) and the aqueous gels formed by derivatives 2 and 3 shownin FIGS. 4( b) and (c), respectively.

The images of their xerogels reveal two different types of morphologies.The organogel formed in acetonitrile by derivative 1 showed ‘grass’ likemorphology. Hydrogels of derivatives 2 and 3 showed helical ribbonmorphology at microscopic level. Analysis of these aggregates clearlyshowed that the individual fibers are approximately 50 nm in width,about 100-125 nm in pitch, and up to several micrometers in length.These helical nanofibers are entangled and formed a dense fibrousnetwork resulting in immobilization of the solvent. Gels were also madein the presence of the drug curcumin, and SEM images suggest thatinclusion of curcumin does not change the basic twisted fibrousmorphology of the hydrogel. See FIG. 5, which are scanning electronmicrographs of curcumin embedded hydrogels of derivative 3.

XRD Measurements and Crystal Structure Analysis

From X-ray diffraction patterns of the xerogels of derivatives 1-3prepared from xylene and water, the long spacings (d) were calculatedand discussed to postulate the possible mode of aggregation in the gelstate. Possibly lamellar structures were formed by these amphiphiles ingels. The xerogels of derivatives 1-3 were prepared by afreezing-and-pumping method and were sponge-like materials. Amygdalinbutyrate (derivative 1) gave a single crystal in water that wassuccessfully analyzed by X-ray crystallography. The crystal structure ofderivative 1 is shown in FIG. 6, which are: (a) the crystal structureanalysis of derivative 1 in water; and, (b) a top view showing the π-πstacking of phenyl rings and hydrogen boding between two amygdalinmolecules, wherein hydrogen bonding acts as a bridge between the stackedamygdalin molecules along the b-axis shown as blue arrows and betweenthese two stacks along the a-axis shown as black arrows, and wherein:oxygen is shown as red; nitrogen is shown as blue; carbon is shown aswhite circles; and, hydrogen-bonding is shown as black dashed lines. Theinformation obtained from the single crystal analysis was combined withthe XRD data to postulate possible molecular packing of amygdalinamphiphiles within the hydro- and organogels.

Drug Encapsulation and Enzyme Triggered Controlled Release

Solubilization of hydrophobic drugs and developing suitable drugdelivery systems is a challenging task in drug discovery research.¹⁸ Aconceptual approach of single-step enzyme-triggered drug delivery atphysiological conditions was performed where a hydrophobic drug moleculewas encapsulated—solubilized without chemical modification—in a hydrogeland subsequent release of the drug by breaking the gel by usinghydrolase enzyme (Lipolase 100L, Type EX). The preformed hydrogel wasdegraded completely by the lipolase while the encapsulatedchemopreventive hydrophobic drug curcumin was released. See FIGS. 1( b)and (c) for images of curcumin. Drug release was monitored by absorbancespectra of the drug. Control of the drug release rate was achieved bymanipulating the enzyme concentration and/or temperature. Theby-products formed after the gel degradation were characterized and thecleavage site of the gelator by enzyme was determined. Gel degradationoccurred due to the cleavage of the ester bond in the gelator by thehydrolase enzyme. ¹⁸Miyata, T., Uragami, T. & Nakamae, K.Biomolecule-sensitive hydrogel. Adv. Drug Delivery Rev. 54, 79-98(2002).

Discussion

Gelation is the delicate balance between solubility and precipitation.To obtain this, the structural features in the gelator molecules need tobe fined tuned.

The amphiphiles of derivatives 1-3 were generated by attaching a fattyacid chain to amygdalin via regiospecific transesterification reactionon a primary sugar hydroxyl. Inspection of FIG. 3 reveals that theamygdalin derivatives are versatile gelators for water andpolar/nonpolar organic solvents, derivative 1 formed gels in twosolvents out of ten tested, whereas derivative 3 gelled in all tensolvents. This explains the importance of chain length on gelationability. Noteworthy to mention is that derivatives 2 and 3 did notrequire any co-solvent to form the hydrogel despite their gelationability in less polar solvents like benzene, toluene, and xylene. Thesegelators showed excellent gelation in a broad range of solvents.

Robustness of a gelator can be determined by considering threeparameters: i) gelation ability in a broad range of solvents; ii) lowminimum gelation concentration (MGC); and, iii) thermal stability of thegels.

For example, these gelators—derivatives 2 and 3—formed gels in highlypolar solvents like water, methanol, and non-polar solvents like nonane,benzene, and toluene. Minimum gelation concentration (MGC) of these gelsare very low, typically 0.05 and 0.2 wt % for derivative 3 in water andbenzene, respectively. This is one of the lowest gelation concentrationsreported in the literature for any class of gelators.¹⁹ Similarly, theother derivatives also exhibit lower MGC values for various solventstypically between 0.07 to 0.5 wt %. In addition, they show good thermaland temporal stabilities. ¹⁹van Bommel, K. J. C., Stuart, M. C. A.,Feringa, B. L. & van Esch, J. Two-stage enzyme mediated drug releasefrom LMWG hydrogels. Org. Biomol. Chem. 3, 2917-2920 (2005); Kobayashi,H. et al. Molecular design of “super” hydrogelators: understanding thegelation process of azobenzene-based sugar derivatives in water. Org.Lett. 4, 1423-1426 (2002).

Gel to solution transition temperature (T_(gel)) was determined bytypical ‘inversion tube method’²⁰ and from differential scanningcalorimeter (DSC). The T_(gel) values of these gels were in the range of40 to 85° C. for 0.5 wt % gels depending on the solvent used. All gelswere stable for months. Hence, together satisfying all three parameters,the reported amygdalin based gelators could be considered as excellentgelators. ²⁰Menger, F. M. & Caran, K. L. Anatomy of a gel. Amino acidderivatives that rigidify water at submillimolar concentrations. J. Am.Chem. Soc. 122, 11679-11691 (2000).

In X-ray diffraction experiments, p-xylene gel of derivative 2 showedlong distance spacing of 4.3 nm, which is higher than the molecularlength—2.8 nm from the optimized geometry calculations—and much lowerthan double that of the extended molecular length of derivative 2. Thus,there could be two possible ways to explain how these molecules couldform self-assembly, which is shown in FIGS. 7( a) and (b), which areschematic representations of possible molecular packing models for the:(a) hydrogels; and, (b) organogels of derivative 2. First, a highlyinterdigitated bilayer structure with the alkyl chain tilting withrespect to the normal to the layer plane shown in FIG. 7( a), andsecond, the hydrophilic parts face inside the assembly and hydrophobicchains are exposed to the outer side of the assembly shown in FIG. 7(b). On the other hand, the long distance spacing for the hydrogel ofderivative 2 is 4.0 nm strongly supports that interdigitated molecularpacking would be possible at the nanoscopic level. It is unlikely thathydroxyls containing sugar headgroup will face inside and lipophilichydrocarbon chains face bull polar solvent, hence model shown in FIG. 7(b) would be ruled out. Thus, molecular packing in the hydrogels ofderivative 2 would be similar to that shown in FIG. 7( a). In thismodel, hydrophilic groups are exposed to the outer solvent whilehydrophobic chains are highly interdigitated, which is consistent withprevious reports.²¹ On the basis of long distance spacing of thehydro-and organogels of derivative 3, it is proposed that most likelythe molecular packing of the amphiphiles are similar to the gels of 2and it might be possible that in the case of the gels of derivative 3,the allyl chain tilt would be more than that of derivative 2. Therefore,layered structures for self-assembly of these gels are also supported bytheir solid-state crystal structure. ²¹John, G., Masuda, M. & Shimizu,T. Nanotube formation from renewable resources via coiled nanofibers.Adv. Mater. 13, 715-718 (2001); Gronwald, 0. & Shinkai, S.Sugar-integrated gelators of organic solvents. Chem. Eur. J. 7,4328-4334 (2001).

Amygdalin butyrate—derivative 1—gives single crystals in water. Theisolated single crystal was successfully analyzed by X-raycrystallography. Interestingly, these molecules were well packed in thecrystal lattice due to the extensive hydrogen bonding. Strongwell-arranged intra- and inter-molecular hydrogen bonding was observed.Intramolecular hydrogen bonding between N (nitrogen) of the nitrilegroup and of sugar hydroxyl (O—H) hydrogen helps to form a lockedconformation that apparently participated in forming the stackedstructures.

Stacked layered structure was stabilized by π-π stacking and van derWaals interactions between the alkyl chains. These two stacks werearranged in ‘head-to-tail’ fashion to give the extended porous structureshown in FIG. 6( b).

Water molecules were involved in two types of hydrogen bonding. In onetype, water molecules formed hydrogen bonding with sugar hydroxyls whileacting as bridged molecules between stacked amygdalin amphiphiles andstabilized the stacked layers as shown in open arrows in FIG. 6( b). Inthe second mode, water molecules were involved in hydrogen bonding withsugar hydroxyls while acting as bridged molecules between two differentstacks of amygdalin amphiphiles to stabilize the two adjacent layers asshown in filled arrow in FIG. 6( b). In addition to that, theintermolecular hydrogen bonding between sugar hydroxyls of two amygdalinmolecules from opposite stacks, which also indicates the greater abilityto form self-assembled structures by amygdalin derivatives, wasobserved.

By collecting the information from the crystal structure of derivative1, most likely in the gel state similar self-assembly would be possible.Previously in literature two reports explained the aggregation modes ofthe gelators based on single crystal analysis.²² As evidenced in thecrystal structure, there are several interactions, such as extensivehydrogen bonding, π-π stacking, and van der Waals interactions existing.Such cooperative interactions play an important role in stabilizing thefiber structures in the gel state. ²²Kiyonaka, S. et al. Semi-wetpeptide protein array using supramolecular hydrogel. Nat. Mater. 3,58-64 (2004); Kumar, D. K., Jose, D. A., Das, A. & Dastidar, P. Firstsnapshot of a nonpolymeric hydrogelator interacting with its gellingsolvents. Chem. Commun. 32, 4059-4062 (2005).

The possible applications of these robust gels to utilize thehydrophobic pockets within the gel to encapsulate hydrophobic drugs wereinvestigated. Hence, these hydrogels were tested as a drug deliveryvehicle model. In the process of developing drug delivery systems,chemical modification of the drug and cleavage induced by externalstimuli, such as increasing temperature followed by enzyme-mediatedcleavage, has been shown recently.²³ Such an approach has limitationswhen applying to different drugs. Covalently connecting the drugs to thehydrogelators may not be achievable trivially in all types of drugs. Inthe process of chemical modification, there is a potential chance ofloosing its original drug activity. It would be an ideal system to haveencapsulated drug models, where drug release can be triggered by enzymeswithout the need of altering pH or temperature. An enzyme triggered drugdelivery at physiological condition was demonstrated where a hydrophobicdrug molecule was encapsulated—solubilized without chemicalmodification—in an hydrogel. Subsequent release of the drug was bybreaking the gel with an hydrolase enzyme (Lipolase 100L, Type EX).²³van Bommel, K. J. C., Stuart, M. C. A., Feringa, B. L. & van Esch, J.Two-stage enzyme mediated drug release from LMWG hydrogels. Org. Biomol.Chem. 3, 2917-2920 (2005).

The success of this approach in drug delivery model systems for possiblein vivo applications rely on a few factors, such as: (a) selectedhydrogels should be able to provide the hydrophobic pockets tosolubilize the hydrophobic drugs; (b) gel degradation—to release thedrug—should take place at mild conditions like physiological pH andtemperature; and, (c) the products formed after degradation should bebiocompatible.

Selected as a model drug was one of the best-characterizedchemopreventive agents, curcumin—or diferuloylmethane²⁴—extracted fromthe root of Curcuma longa, which presents strong anti-oxidative,anti-inflammatory, and antiseptic properties.²⁵ In addition, curcuminalso inhibits purified human immunodeficiency virus type 1 (HIV-1)integrace,²⁶ HIV-1 and HIV-2 proteases,²⁷ and HIV-1 long terminalrepeat-directed gene expression of acutely or chronically infected HIV-1cells.²⁸ Despite such astounding drug activity, unfortunately curcuminhas an extremely low aqueous solubility and poor bioavailabilitylimiting its pharmaceutical use.²⁹ One possible way to increase itsaqueous solubility is to form inclusion complexes, i.e. to encapsulatecurcumin as a guest within the internal cavities of a water-soluble hostor encapsulate within the nanoaggregates—formed by self-assembly—thathave hydrophobic pockets within. ²⁴Duvoix, A. et al. Chemopreventive andtherapeutic effects of curcumin. Cancer Lett. 223, 181-190 (2005). L6²⁵Hergenhahn, M. et al. The chemopreventive compound curcumin is anefficient inhibitor of Epstein-Barr virus BZLF1 transcription in RajiDR-LUC cells. Mol. Carcinog. 33, 137-145 (2002).²⁶Hergenhahn, M. et al.The chemopreventive compound curcumin is an efficient inhibitor ofEpstein-Barr virus BZLF1 transcription in Raji DR-LUC cells. Mol.Carcinog. 33, 137-145 (2002); Mazumder, A., Raghavan, K., Weinstein, J.,Kohn, K. W. & Pommier, Y. Inhibition of human immunodeficiency virustype-1 integrase by curcumin. Biochem. Pharm. 49, 1165-1170(1995).²⁷Burke, T. R. Jr. et al. Hydroxylated aromatic inhibitor ofHIV-1 integrase. J. Med. Chem. 38, 4171-4178 (1995).²⁸Sui, Z., Salto,R., Li. J., Craik, C. & Ortiz de Montellano, P. R. Inhibition of theHIV-1 and HIV-2 proteases by curcumin and curcumin boron complexes.Bioorg. Med. Chem. 1, 415-422 (1993).²⁹Khodpe, S. M., Priyadarsini, K.I., Palit, D. K. & Mukherjee, T. Effect of solvent on the excited-statephotophysical properties of curcumin. Photochem. Photohiol. 72, 625-631(2000).

Schematic representation of curcumin encapsulation and enzyme-mediatedrelease is depicted in FIG. 8( a) wherein FIG. 8 are (a) a schematicrepresentation of drug encapsulation in a supramolecular hydrogel andsubsequent release of the drug by enzyme-mediated degradation ofhydrogel at physiological temperature; and, (b) real images of thehydrogels of derivative 3 with (I-iv) and without (v-vi) curcumin,wherein after complete gel degradation, the remained white fluffy powderthat settled at the bottom was characterized as a water insoluble fattyacid that formed after gel degradation by the enzyme. The release ofcurcumin into the solution in the presence of enzyme was monitored bymeasuring the curcumin UV-absorption spectrum. The absorption spectrumrecorded in aqueous gel solution was compared with the curcumin spectrarecorded in methanol. The effect of solvent polarity on the absorbancespectrum of curcumin has previously been reported as minimal.³⁰ Highconcentration of curcumin (1×10⁻³ M) was solubilized in 0.5 wt %hydrogel of derivative 3—reported³¹ solubility of curcumin in water is3×10⁻⁸ M, i.e., ˜33,000 times more than solubilized in the hydrogel. Theresulted gel was yellow in color as shown in FIG. 8( b), and due to thehydrophobic nature, curcumin might be located at hydrophobic pockets ofthe gel. To test this hypothesis, water was added to the preformed geland left for 12 hrs. The UV-absorption of the supernatant was recorded.Absence of any absorbance peak concluded the unavailability of curcuminon the gel surface by adsorption. ³⁰Id.³¹Tonnesen, H. H., Másson, M. &Loftsson, T. Studies of curcumin and curcuminoids. XXVII. Cyclodextrincomplexation: solubility, chemical and photochemical stability. Int. J.Pharm. 244, 127-135 (2002).

First, 0.5 mL of lipase—Lipolase 100L, Type EX, lipase units 100KLU/g—was added to the preformed gel and kept at 37° C.—far lower thangel melting temperature. Initially the added solution was colorless asshown in FIG. 8( b)(iii). After 12 hrs visual changes occurred as shownin FIG. 8( b)(iv), i.e., 100% of the gel has been degraded and the topsolution has became yellow in color, which indicates that upon enzymemediated gel degradation, encapsulated curcumin has been released intothe solution. This was confirmed by spectroscopic experiments. Aliquotswere collected after addition of an enzyme to the hydrogel after 10 minand 12 hrs and absorbance spectrum were recorded. Interestingly, initialaliquots after 10 min did not show any absorbance peak, but aliquotscollected after 12 hrs showed absorption maxima at 425 nm, whichcorresponds to the absorption peak of curcumin. See FIG. 9, which are UVabsorption spectra of curcumin in various types of solution mixtures,including: (a) an curcumin-entrapped hydrogel in the presence of anenzyme; (b) an enzyme added to the hydrogel that does not containcurcumin; (c) an curcumin-entrapped hydrogel in the absence of anenzyme; and, (d) a methanolic solution of curcumin.

To find out the role of the enzyme on hydrogel degradation, similarexperiments were carried out by adding only water without an enzyme. Asexpected, the curcumin-encapsulated gel was still intact afterincubating for a few days at 37° C. There was no visual change in thegel volume and in the added solution. See FIG. 8( b). And, theabsorbance peak corresponding to the curcumin was not shown. See FIG. 9(a). In addition, control experiments with the same hydrogel ofderivative 3 without curcumin, which is opaque and white in color asshown in FIG. 8( b), were performed. To this, 0.5 mL of lipolase wasadded and incubated at 37° C. After 12 hrs, the gel degraded completely.The absorption spectrum of the solution shown in FIG. 9( b) was thenrecorded. Absence of the absorption peak at 425 nm suggested that thepreviously observed peak, FIG. 9( c), corresponded to the curcuminreleased into the solution.

To obtain control on the rate of release, the role of enzymeconcentration and temperature on gel degradation or controlled drugrelease was investigated. In a first set of experiments, the temperaturewas changed while keeping enzyme concentration constant. After additionof the enzyme to the preformed gel, the vial was kept at roomtemperature for two days, and as explained previously, curcumin releasewas monitored by absorption spectra. Interestingly, even after two daysat room temperature in the presence of the enzyme, there was no geldegradation observed, and thus, there was no release of encapsulatedcurcumin. When the vial was placed at 37° C. in an incubator, after 120min slow release of curcumin was observed, and within 720 minencapsulated curcumin was released completely. Similarly when incubatedat 45° C., release was initiated within 30 min and complete release wasobserved in 270 min.

In a second set of experiments, the enzyme concentration was changedwhile keeping the temperature constant. 10 times lower concentratedlipolase—units 10 KLU/g—added to the preformed curcumin encapsulatedgel. At room temperature, even after several days, there was no release.Then the vial was placed at 37° C. in incubation and took 300 min tostart the drug release, which eventually took 4,320 min to releasecompletely. In addition to this, a similar low enzyme concentrated vialwas directly incubated at 45° C. In this case, drug release was startedafter 180 min and in 2,880 min complete release was observed. Hence atconstant temperature, drug release can be controlled by lowering theenzyme concentration. These results are summarized in FIG. 10, which isa table of the effect of enzyme concentration and temperature on drugrelease time, and FIG. 11, which are a comparison ofcurcumin-drug-release time at different concentrations and differenttemperatures from hydrogels of amygdalin derivatives by enzymedegradation, wherein: (a) is the time required for 5% release; and, (b)is the time required for 100%—which clearly demonstrate the achievedcontrol over the release of an encapsulated drug from a hydrogel.

It is important to characterize the products/compounds formed after geldegradation. To find out the other components formed after geldegradation, thin layer chromatography (TLC) of the solution wasperformed and it was found that this solution contains amygdalin,curcumin, and enzyme—confirmed by comparing R_(f) values. This indicatesthat the enzyme is degrading the gel by cleaving the ester bond ofderivative 3. Upon gel degradation, a white fluffy solid was produced,which is not soluble in water, and thus settled down in the vial. SeeFIG. 8( b)(iv). The solid was isolated and characterized by ¹H-NMR, andit matched with the NMR of pure stearic acid. See FIG. 12, which is acomparison of the ¹H-NMR spectra of commercially available stearic acidand the white fluffy solid obtained after gel degradation, which wasfiltered, freeze-dried, and NMR recorded in Chloroform. Hence, it isundoubtedly suggesting that gel degradation is occurring through thecleavage of the ester bond of amygdalin derivatives by lipolase enzyme.

These results unambiguously explain the drug encapsulation abilities ofhydrogels formed by amygdalin derivatives and enzyme-triggered drugrelease. Noteworthy, these gelators were generated via enzyme catalysis,and gels were degraded—converting from gelators to starting materials—byyet again using enzyme catalysis in environmentally benign conditions.

Methods General Information

Amygdalin and curcumin was purchased from Acros Chemicals (FisherScientific Company, Suwane, Ga.). The Novozyme 435 [lipase B fromCandida Antarctica, (CALB)] and Lipolase 100L were obtained fromNovozymes through Brenntag North America. Other reagents were obtainedfrom TCI America (Portland, Oreg.).

General Synthesis Procedure of Amygdalin Esters by Enzyme Catalysis

Typically, 40 ml of acetone containing 0.1 mol/L amygdalin and 0.3 mol/Lvinyl esters—vinyl butyrate, vinyl myristate, and vinyl stearate—wasadded to 1 g of Novozyme 435. The reaction mixtures were placed in anincubator and shook at 200 rpm at 45° C. for 48 hr. The reactions wereterminated by the filtration of reaction mixtures. After evaporating thesolvent, the obtained crude products were purified by silica gel flashchromatography using ethyl acetate—methanol (4:1) as eluent, affordedpure products as white solids. The yields were above 90% for allreactions.

Amygdalin Butyrate—Derivative 1

¹H-NMR, (Acetone-d₆, 300 MHz) δ 7.58 (m, 2H), 7.48 (m, 2H), 7.46 (m,1H), 5.98 (s, 1H), 5.1-5.33 (br m, 6H), 4.45 (d, 1H), 4.29 (d, 1H), 4.22(dd, 1H), 4.04 (dd, 1H), 3.99 (dd, 1H), 3.59 (dd, 1H), 3.38 (m, 1H),3.35 (m, 1H), 3.25 (m, 2H), 3.18 (m, 2H), 3.13 (m, 1H), 3.1 (m, 1H), 2.2(t, 2H), 1.24 (m, 2H), 0.83 (t, 3H). Anal. Calcd. for C₂₄H₃₃NO₁₂: C,54.64; H, 6.31; N, 2.66. Found: C, 54.68; H, 6.30; N. 2.70.

Amygdalin Tetradecanoate—Derivative 2

¹H-NMR, (CDCl₃, 300 MHz) δ 7.58 (m, 2H), 7.48 (m, 2H), 7.46 (m, 1H),5.98 (s, 1H), 5.1-5.33 (br m, 6H), 4.45 (d, 1H), 4.29 (d, 1H), 4.22 (dd,1H), 4.04 (dd, 1H), 3.99 (dd, 1H), 3.59 (dd, 1H), 3.38 (m, 1H), 3.35 (m,1H), 3.25 (m, 2H), 3.18 (m, 2H), 3.13 (m, 1H), 3.1 (m, 1H), 2.2 (t, 2H),1.24 (m, 22H), 0.83 (t, 3H). Anal. Calcd. for C₃₄H₅₃NO₁₂: C, 61.15; H,8.00; N, 2.10. Found: C, 61.20; H, 8.02; N. 2.14.

Amygdalin Octadecanoate—Derivative 3

¹H-NMR, (CDCl₃, 300 MHz) δ 7.58 (m, 2H), 7.48 (m, 2H), 7.46 (m, 1H),5.98 (s, 1H), 5.1-5.33 (br m, 6H), 4.45 (d, 1H), 4.29 (d, 1H), 4.22 (dd,1H), 4.04 (dd, 1H), 3.99 (dd, 1H), 3.59 (dd, 1H), 3.38 (m, 1H), 3.35 (m,1H), 3.25 (m, 2H), 3.18 (m, 2H), 3.13 (m, 1H), 3.1 (m, 1H), 2.2 (t, 2H),1.24 (m, 30H), 0.83 (t, 3H). Anal. Calcd. for C₃₈H₆₁NO₁₂: C, 63.05; H,8.49; N, 1.93. Found: C, 63.11; H, 8.51; N. 1.95.

Preparation of Supramolecular Gels: Self-Assembly

Typically, the gelator (0.01-2 mg) and required solvent (0.1-1 mL) wereplaced into a 2 mL scintillation vial, which was then sealed with ascrew cap. The vial was heated and shook until the solid was completelydissolved. The solution was set aside and allowed to cool to roomtemperature. Gelation was considered to have occurred when nogravitational flow in the inverted tube was observed.

Gel Melting Temperatures

The Gel to Sol transition temperature (T_(gel)) was determined by twomethods. One was the typical ‘inversion tube method’,³² where the gelwas prepared in a 2 mL glass vial by dissolving a 0.5 wt % gelator in arequired amount of solvent and closed with a tight screw cap. The vialwas immersed in water ‘up side down’ and slowly heated. The temperaturewhere the viscous gel melted and dropped down was considered as theT_(gel). The second method, T_(gel) was determined by using a MettlerDSC-822 Differential Scanning Calorimeter equipped with a nitrogen-gasintra cooling system. The gel was hermitically sealed in a silver panand measured against a pan containing alumina as reference. Thermogramswere recorded at a heating rate of 5° C./min. The T_(gel) valuesdetermined by these two methods were identical. ³²Menger, F. M. & Caran,K. L. Anatomy of a gel. Amino acid derivatives that rigidify water atsubmillimolar concentrations. J. Am. Chem. Soc. 122, 11679-11691 (2000).

Observation of Gel Structure by Microscopy

The xerogel samples were prepared by the freezing-and-pumping methodfrom their gel phases below the sol-gel transition temperature. It isimportant to note that the SEM images of xerogels and the followingdrying under ambient condition show similar morphologies. Therefore,morphology with the gels dried under ambient conditions, which wascalled xerogels, was studied.

X-Ray Powder Diffraction (XRD)

XRD measurements were conducted using a Bruker AXS D-8 Discover withGADDS diffractometer using graded d-space elliptical side-by-sidemultilayer optics, monochromated Cu—Kα radiation (40 kV, 40 mA), and animaging plate. The gels were used as prepared in the wet condition forthe analysis. A small portion of the gel sample was transferred to thesample holder and sealed off immediately using capstone tape to avoidany drying off of the solvent. The typical exposure time was 1 min forself-assembled structures with a 100 mm camera length.

X-Ray Single Crystal Analysis

X-ray quality colorless single crystals of derivative 1 were obtainedfrom water in a flat rod shape. X-ray diffraction data were collectedusing Mo—Kα (λ=0.7 107 Å) radiation on a graphite monochromatized BrukerX8 APEX II diffractometer at 173(2) K. Data collection, data reduction,and structure solution refinement were carried out using the softwarepackage of SHELX97.³³ All structures were solved by direct methods(S1R92) and refined in a routine manner. Non-hydrogen atoms were treatedanisotropically. Whenever possible, the hydrogen atoms were located on adifferent Fourier map and refined. The crystallographic parameters arelisted in FIG. 13, which is a table of the crystallographic parametersof derivative 1. ³³Sheldrick, G. M. SHELEXL-97, A program for crystalstructure solution and refinement; University of Göttingen: Göttingen,Germany, 1993.

Conclusions

In conclusion, hydro/organogelators from renewable resources weresuccessfully developed. Low-molecular-weight hydrogelators weresynthesized by regioselective enzyme catalysis for the first time.Yields were quantitative and crude reaction mixtures exhibited equallyunprecedented gelation properties like their counter pure products. Thiscapability may allow development of hydrogelators in industrial scalefor future applications.³⁴ The hierarchical structural characteristic ofsupramolecular gels were clearly demonstrated and the self-assemblybased on XRD and single crystal analysis were explained. ³⁴Zhang, S.Hydrogels: Wet or let die. Nat. Mater. 3, 7-8 (2004).

The gel fibers were self-assembled and stabilized by variousinteractions, such as intra- and inter-molecular hydrogen bonding, π-πstacking, and van der Waals interactions. The encapsulation ofchemopreventive curcumin in the hydrogel was shown, and enzyme-triggeredgel degradation was performed to release the encapsulated drug into thesolution at physiological temperature. Controlled drug release rate wasachieved by manipulating the concentration of enzyme or temperature.

The by-products formed after gel degradation were characterized andclearly demonstrated the site specificity of degradation of the gelatorby enzyme catalysis. Supramolecular chemistry is now a powerful strategyfor developing new molecularly defined materials in material andmedicinal science. This would be a possible model system for drugencapsulation and enzyme mediated delivery for in vivo formulations andmay have potential applications in pharmaceutical research and moleculardesign of value added products from biobased materials, otherwise underutilized.

It will be understood that each of the elements described above or twoor more together may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in amethod for preparing hydro/organo gelators from disaccharide sugars bybiocatalysis and their use in enzyme-triggered drug delivery, however,it is not limited to the details shown, since it will be understood thatvarious omissions, modifications, substitutions, and changes in theforms and details of the device illustrated and its operation can bemade by those skilled in the art without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting features thatfrom the standpoint of prior art fairly constitute characteristics ofthe generic or specific aspects of the invention.

1.-11. (canceled)
 12. A drug-delivery composition, comprising: a) ahydro/organo gel prepared from disaccharide sugars or derives thereof;and b) a hydrophobic drug encapsulated in said gel; wherein said drug iscapable of release upon enzyme mediated degradation of said gel.
 13. Thecomposition of claim 12, wherein the hydro/organo gel is prepared byself-assembly of hydro/organo gelators prepared from a disaccharidesugar or derivatives thereof via a biosynthesis reaction.
 14. Thecomposition of claim 12, wherein the disaccharide sugar is amygdalin.15. The composition of claim 12, wherein the gelator is anesterification reaction product of a fatty acid and amygdalin.
 16. Thecomposition of claim 15, wherein the gelator is selected from the groupconsisting of amygdalin butyrate, amygdalin tetradecanoate, andamygdalin octadecanoate.
 17. The composition of claim 12, wherein thehydrophobic drug is curcumin and the gelator is an amygdalin-derivedgelator.
 18. A method for preparing hydro/organo gelators, comprisingthe step of attaching a fatty acid chain to disaccharide sugars via aregiospecific transesterification reaction on a primary sugar hydroxylvia enzyme catalysis.
 19. The method as described in claim 18, whereinthe said disaccharide sugar is amygdalin.
 20. The method as described inclaim 18, wherein the glator is selected from the group consisting ofamygdalin butyrate, amygdalin tetradecanoate, and amygdalinoctadecanoate.
 21. The method as described in claim 18, where the saidcatalyzing enzyme is a lipase or a lipolase.
 22. A method for usinghydro/organo gelators for drug delivery or cosmetic delivery, comprisingthe steps of: a) encapsulating and solubilization of a hydrophobic drugmolecule or a hydrophobic molecule which is a component of a cosmeticformula in a hydrogel; and b) releasing the drug or the hydrophobiccosmetic molecule by using a gel-breaking enzyme.
 23. The method asdescribed in claim 22, where the gel-breaking enzyme is a hydrolase. 24.The method as described in claim 22, where the activity of thegel-breaking enzyme is controlled by physiological temperature andconcentration.
 25. A method of using hydro-organo gelators prepared fromdisaccharide sugars in generating inorganic nanomaterial template.